Original oblique sections of the retroperitoneum: radio-anatomic basis

Summary The authors present oblique sections of the retroperitoneum adapted to the morphology of each patient, which affects both the liver and the organisation of the retroperitoneum. This original method involve two incidences for studying the left and right retroperitoneum separately with vertical sectional planes. The authors postulate that the orientation of the retroperitoneal viscera depends on the degree of hepatic development, so these incidences are chosen with reference to axial sections of the portal bifurcation and the middle hepatic v.: the two vascular landmarks of the liver. Anatomic and radiologic studies confirm the reliability of these landmarks and their easy application in modern imaging. Such new data improve our understanding of the classical topographic anatomy of the retroperitoneum. These oblique sections promote the radiologic study of the portal and systemic vessels, renal pedicles, suprarenal glands and pancreas.

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Coupes obliques originales du rétropéritoine. Bases anatomo-radiologiques

Résumé Les auteurs proposent une méthode de coupes obliques du rétropéritoine adaptées à la morphologie de chaque individu. En effet, la disposition des viscères rétropéritonéaux, comme celle du foie, varie d'un patient à l'autre en fonction de son morphotype. Cette méthode originale comporte deux incidences destinées à l'étude séparée du rétropéritoine gauche et droit. Il s'agit de deux plans de coupe verticaux, articulés par un axe qui se superpose à celui de la veine porte. Les auteurs supposent que l'orientation des viscères au sein du rétropéritoine dépend du développement du foie, ainsi ces incidences sont choisies grâce à un repérage en coupes axiales de la veine hépatique moyenne et de la bifurcation portale, deux témoins vasculaires de la morphologie du foie. Ces plans de coupe ont fait l'objet d'une étude anatomique puis radiologique qui confirme la fiabilité de ces repères et leur facilité d'application à l'imagerie moderne. Les images obtenues complètent l'Anatomie Topographique classique du rétropéritoine. Ces coupes obliques facilitent l'exploration radiologique des vaisseaux portaux et systémiques, des pédicules rénaux, des glandes surrénales et du pancréas.

     

Magnetic resonance imaging of the heart compared with anatomic and ultrasonographic data

Summary The authors present a correlation study between the anatomy of the heart and its appearance with magnetic resonance imaging (MRI) and ultrasonography (US). Six hearts were studied by MR, then sliced along the same planes. The results are presented and compared with the data obtained in volunteers by MRI and ultrasonography. The correlation between the MRI of isolated hearts and their anatomic slices is excellent, the thiniest anatomic details are reproduced. The use of double oblique slices provides incidences similar to those of ultrasonography. The same incidences can be obtained in vivo. The morphologic study of the heart by these imaging techniques is thus very precise, as well as the study of cardiac volumes.

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Aspect du cur en imagerie par résonance magnétique comparé aux données anatomiques et échographiques

Résumé Les auteurs présentent un travail de corrélation entre l'aspect anatomique du cur et les images obtenues en imagerie par résonance magnétique (IRM) et en échographie. Six curs ont été étudiés par IRM puis découpés suivant les mêmes plans de coupe. Les résultats sont présentés et comparés aux données obtenues in vivo chez des volontaires à la fois en IRM et en échographie. La corrélation entre images IRM de pièces anatomiques et coupes anatomiques est excellente, les plus fins détails anatomiques étant reproduits. L'utilisation de coupes en double obliquité permet l'obtention d'incidences similaires à celle de l'échographie. Ces mêmes incidences peuvent être obtenues in vivo. L'étude morphologique du cur est ainsi extrêmement précise, de même que l'étude des volumes cardiaques.

     

健康儿童颈髓磁共振扩散张量成像

目的 应用扩散张量成像技术研究儿童颈髓发育规律。方法 使用单次激发自旋回波平面回波序列对90例健康儿童行颈髓扩散张量成像。在颈髓节段分别测量其表观扩散系数值（ADC）、各向异性分数值（FA）、纤维束平均长度（Ltract）以及纤维束体积（Vtract）。结果 各组的ADC值、FA值、Ltract及Vtract分别如下：0.9747±0.2777、0.8493±0.2236、0.8210±0.1432、0.9198±0.1444、0.9048±0.1676;0.4117±0.0391、0.4712±0.0199、0.4944±0.0439、0.5608±0.0443、0.6169±0.0551;25.61±8.63、24.66±7.14、27.03±7.23、34.93±10.99、37.63±10.22;3.07±1.49、3.00±1.52、3.81±1.33、5.41±2.35、6.64±2.84。各年龄组的FA值、Ltract和Vtract不完全相同（P<0.001）,而ADC值各年龄组的均值差异无统计学意义（F=1.758, P=0.145）。在组间的两两比较中：1、2组间FA值差异具有统计学意义;3、4组间FA值、Ltract和Vtract差异均具有统计学意义;4、5组间FA值差异具有统计学意义。FA值、Ltract和Vtract与年龄呈正相关。
结论 儿童颈髓发育具有阶段性,且具有阶段性特征;磁共振扩散张量技术可用于观测儿童颈髓并评价其发育。     

Muscle cross-section measurement by magnetic resonance imaging

Summary Muscle cross-section areas were measured by magnetic resonance imaging (MRI) in the thigh of a human cadaver,. the results being compared with those obtained by photography of corresponding anatomic macroslices. A close correlation was found between MRI and photographic evaluation, differences between the methods ranging from nil to 9.5%, depending on the scan position and the muscle groups. In vivo MRI measurements were performed on 12 female and 16 male students, the objectivity, the test-retest reliability and the variability of the MRI measurements being studied by fixing the scan position either manually or by coronary scan. The latter method appeared to be more objective and reliable. The coefficients of variation for muscle cross-section areas measured by MRI were in the range of those for the planimetry of given cross-section areas. Allowing for differentiation between several small muscle bundles in a given area, MRI proved to be a suitable method to quantify muscle cross-sections for intra- and interindividual analysis of muscle size.     

Magnetic resonance imaging of the liver by frontal (coronal) sections

In general, frontal sections of the liver in magnetic resonance imaging are used less than sections passing through other planes of space. Frontal sections of the trunk in magnetic resonance imaging involving the liver, performed in over 80 patients for various reasons, were compared with frontal sections of the trunk made in 10 cadavers. A general schema was established of the anatomy of the liver studied in the frontal plane. Frontal sections in magnetic resonance imaging make it possible to form a very good estimate of the structure and size of the liver, and to recognize individual variations. They clearly show certain inferior relations of the liver. In particular, frontal sections in magnetic resonance imaging make it possible to identify most of the main veins of the liver, the main lobar veins and branches of the portal vein, and to properly study the entire retrohepatic portion of the inferior vena cava. Some of the vascular images were found almost constantly in the sections of the various subjects. The right lobe of the liver is more accessible to such study than the left by reason of its structure and its venous arrangements. Frontal sections of the liver in magnetic resonance imaging constitute a preferential method for studying the anatomy of the liver. Together with transverse sections, they make it possible to specify the site and venous relations of a pathologic process within the liver, with a view to hepatectomy.     

Anatomic correlation of cadaver cryomicrotomy with magnetic resonance imaging

Summary The performance of frozen sections of a thickness varying between 5 and 50 m in fresh undecalcified cadaveric human specimens was perfected in Sweden by one of the authors in 1983. This technique makes it possible to obtain anatomic images of high definition which were correlated with MRI sections made at intervals of 20 m.

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Corrélations anatomiques entre la cryomicrotomie sur cadavre et l'IRM

Résumé La réalisation de coupes congelées dont l'épaisseur varie entre 5 et 50 m, sur prélèvements cadavériques humains frais et non décalcifiés a été mise au point en Suède par l'un des auteurs en 1983. Cette technique permet d'obtenir des images anatomiques de haute définition qui ont été corrélées avec des coupes en IRM réalisées à des intervalles de 20 m.

     

成人与儿童髓母细胞瘤的MRI特征分析

目的 分析成人与儿童髓母细胞瘤的MRI表现,提高对髓母细胞瘤的认识。方法 回顾性分析2009年1月—2017年12月广东省农垦中心医院经手术病理证实的髓母细胞瘤36例的影像学资料。将其分为两组:儿童组(＜18岁)25例,成人组(≥18岁)11例。36例患者术前行MRI平扫及增强扫描,观察并对比分析两组患者肿瘤的发生部位、瘤体最大径线、边界、囊变、实性部分强化程度、瘤周水肿、梗阻性脑积水、室管膜种植转移等影像学特征。结果 36例髓母细胞瘤均发生于幕下,儿童常见于小脑蚓部(21/25),成人病灶多位于小脑半球(9/11),差异有统计学意义(P=0.000)。儿童肿瘤最大径为(4.50±0.58) cm,其中17例肿瘤最大径超过4 cm;成年人瘤体最大径为(5.24±1.36) cm,其中8例肿瘤最大径超过4 cm;两者比较差异无统计学意义(Z=-0.895, P＞0.05)。成人组和儿童组囊变分别有16例和11例,瘤周水肿分别有4例和7例,差异均有统计学意义(P=0.034、0.008);而边界、梗阻性脑积水及室管膜种植转移方面组间差异均无统计学意义(P值均＞0.05)。36例患者髓母细胞瘤实性部分均表现为T₂WI及T₂WI-FLAIR稍高信号,T₁WI等偏低信号。12例做了弥散加权成像检查(5例儿童、7例成人),瘤体实性部分均表现为弥散受限;增强后,两组肿瘤实性区域均表现为轻度至中度强化。结论 儿童髓母细胞瘤好发于小脑蚓部,成人以小脑半球多见;儿童肿瘤囊变及瘤周水肿相对于成年人少。儿童与成人髓母细胞瘤均常表现为边界清楚肿块,实性区域轻度至中度强化,易发生梗阻性脑积水,可发生室管膜种植转移。     

酪氨酸酶基因在HEK293细胞表达的MRI评价

目的:以酪氨酸酶基因作为报告基因转染HEK293细胞, 利用其合成大量黑色素而能被MRI检测的特性来反映基因表达的情况, 以探索磁共振成像(MRI)评价体外细胞基因表达的方法。方法:以脂质体将含酪氨酸酶基因完全cDNA的pcDNA3tyr质粒转染到HEK293细胞, 以MRIT₁WI、T₁WI/SPIR、T₂WI序列扫描转染细胞, 观察表达的黑色素的MRI信号。应用Fontana染色检测黑色素的合成, RT-PCR检测酪氨酸酶基因的cDNA片段, 以进一步验证酪氨酸酶基因的转染与表达。结果:(1)pcDNA3tyr质粒转染进入HEK293细胞并在其中表达生成黑色素, 转染5μg、10μg、20μg质粒的10⁶个细胞内生成的黑色素能够被MRI检测到并在MRIT₁WI、T₁WI/SPIR、T₂WI检查呈高信号, MRI信号强度与转染质粒量成正相关。(2)Fontana染色法检测到HEK293细胞内的黑色素颗粒;(3)采用RT-PCR方法检测到转染的HEK293细胞含酪氨酸酶基因的cDNA片段。结论:MRI能够检测到HEK293细胞内由外源基因表达合成的黑色素, 说明影像学与分子生物学技术结合可以评价体外细胞基因表达的情况。     

应用MRI分析腰椎多裂肌-最长肌间隙入口位置

目的 应用MRI测量腰椎各椎间盘平面多裂肌-最长肌间隙入口与中线的距离,并分析其相关因素。方法 前瞻性选取2012年4月—2013年1月行腰椎MRI检查的200例患者,测量腰椎MRI各椎间盘平面双侧肌间隙入口与中线的距离（D）,并采用单因素方差分析和q检验比较节段间差异,t检验比较左右两侧及不同性别的差异,Pearson相关性检验分析各节段D间的相关性,多元线性回归分析各节段D与患者年龄、身高、BMI的相关性。结果 腰椎各椎间盘平面肌间D从L1/2水平至L5/S1水平逐渐增大,不同节段间D差异有统计学意义（左侧：F=3 614.84,P=0.00;右侧：F=3 411.34,P=0.00）,但左右侧间差异无统计学意义（P＞0.05）,D1仅与D2间存在相关性,而D2~D5间则两两正相关。男性与女性患者仅L4/5节段D差异有统计学意义（t=4.44,P＜0.01）,其他节段D男女间差异均无统计学意义（P值均＞0.05）。各节段D与患者的年龄均无相关性。男性患者D1双侧均与身高呈正相关,女性患者D1L、D1R及D2L与BMI正相关,而D4双侧与身高呈正相关。结论 腰椎多裂肌-最长肌间隙入口位置与患者年龄、性别、身高、BMI等关系不大。在L1-3水平,肌间隙距离正中线较近,适合作单个正中切口;在L4～S1水平则应根据术前测量结果应用双侧切口。     

Magnetic resonance imaging of in vivo patellofemoral kinematics after total knee arthroplasty

Simulated partial weight bearing during magnetic resonance imaging of the knee was used to measure patellar tilt, medial–lateral patellar shift, and patellofemoral contact area in three groups of subjects; patients with posterior cruciate retaining (PCR) TKA, patients with bicruciate substituting (BCS) TKA, and healthy controls. Contact stress was also calculated based on the contact area and body weight-based estimates of contact force. Contact stress was significantly (p < 0.05) higher in PCR knees (2.5 ± 3.0 MPa) than in BCS knees (0.2 ± 0.1 MPa) when knees were fully extended, but this difference was not significant (3.7 ± 3.5 MPa for PCR knees vs. 1.4 ± 1.9 MPa for BCS knees; p > 0.05) in early flexion. The results also indicate that patellar tilt (normal = 2.4° ± 4.8°, BCS = 5.5° ± 5.5°, PCR = − 3.0° ± 6.9° change in lateral tilt when moving from full extension to early flexion) and contact area (full extension: normal = 267 ± 111 mm², BCS = 344 ± 201 mm², PCR = 83 ± 80 mm²; early flexion: normal = 723 ± 306 mm², BCS = 417 ± 290 mm², PCR = 246 ± 108 mm²) in BCS TKA mimic those in the normal knees more closely than PCR knees do. These results suggest that the patellar component in BCS TKA may be expected to experience less wear than the patellar component in PCR TKA over time.     

Evolution of healthy thoracic aortic segment diameter during follow-up of patients with aortic aneurysm or dissection: a magnetic resonance imaging study

We studied the normal evolution over time of the diameter of the healthy descending aorta in patients suffering from aneurysm or dissection of the ascending aorta, in order to anticipate potential complications of endoprosthetic treatment in this aortic segment. During their follow-up (average 35.9 months), 52 patients suffering from aneurysm or dissection of the ascending aorta had 168 aortic MRI examinations (27; average 3). Measurements were taken according to conventional reference landmarks making it possible to study the evolution of the diameter of the supposed healthy descending thoracic aorta. The variations in diameter with time were on average 5 mm, and there was no significant variation in this diameter, either for early controls or for the controls carried out after more than 1 year or 3 years, whatever the age group. Thus according to our series it seems that patients with a descending aorta endoprosthesis are not exposed to graft endoleak due to inadequate contact of the prosthesis and aorta within the 5 years following its implantation.     

Non-invasive temperature imaging of muscles with magnetic resonance imaging using spin-echo sequences

The application of spin-echo magnetic resonance imaging sequences on non-invasive temperature imaging for temperature mapping of human limbs is investigated. In an in vitro expriment performed on a meat sample, the equilibrium magnetisation P and the spin-lattice relaxation time T₁ are calculated from the values for the repetition time TR and the signal intensities obtained by a spin-echo sequence at different tissue temperatures tures as measured by a fibre-optic probe. T₁ is linearly correlated to the tissue temperature, and P is linearly correlated to the reciprocal value of the absolute temperature. Both effects, taken together, lead to a non-linear dependency of the signal intensity on temperature. Therefore a TR leading to maximum temperature dependency of the signal intensity is calculated and used in the futher experiments. In the in vivo experiments, the lower legs of two volunteers are cooled from outside. Images are acquired with a spin-echo sequence (1.5T, TR=1200 ms, TE=10 ms). A rise in signal intensity in the muscle with falling skin temperature is observed, particularly in more peripheral muscle layers. This study shows that spin-echo sequences can be used to monitor temperature changes and temperature differences in living muscle tissue.     

足月宫内胎儿脑的矢状断层影像解剖学研究

目的:为给MR矢状图像精确定位宫内胎儿脑发育畸形及胎儿优生优育的MRI筛查提供断层解剖学依据。方法:将1例晚期妊娠尸体做腹盆部矢状位MR扫描,获取图像数据。用电动带锯按等距法制成与正中矢状面平行的腹、盆部连续矢状断层标本,并获取连续矢状断层标本图像数据,显示妊娠晚期宫内胎儿脑组织的形态结构。结果:(1)宫内胎儿头颅的倾斜及旋转方向的确定:胎儿为纵产式、头先露,胎头已经入盆,伴有颈部仰伸,胎体的前后位与孕妇一致,孕妇的正中矢状面图像与胎儿的正中矢状面图像一致,而且胎儿的头颅发生了向自己身体右侧的倾斜和旋转。(2)7幅标本的矢状断面图像是由孕妇左侧向右侧切及获得(胎体的右侧至左侧),分别经胎儿右侧大脑半球外侧凸面、外侧沟、内囊、正中矢状面、小脑中脚及脑干、左侧半球外侧凸面及左侧外侧沟。结论:宫内胎儿脑连续矢状断层标本和对应的MR图像对比分析结果显示了宫内胎儿脑的形态结构特征,能够为胎儿脑组织的胚胎发育和临床影像诊断提供正常的形态学资料。     

Micro-magnetic resonance imaging of avian embryos

Chick embryos are useful models for probing developmental mechanisms including those involved in organogenesis. In addition to classic embryological manipulations, it is possible to test the function of molecules and genes while the embryo remains within the egg. Here we define conditions for imaging chick embryo anatomy and for visualising living quail embryos. We focus on the developing limb and describe how different tissues can be imaged using micro-magnetic resonance imaging and this information then synthesised, using a three-dimensional visualisation package, into detailed anatomy. We illustrate the potential for micro-magnetic resonance imaging to analyse phenotypic changes following chick limb manipulation. The work with the living quail embryos lays the foundations for using micro-magnetic resonance imaging as an experimental tool to follow the consequences of such manipulations over time.     

Response of the trunk muscles to training assessed by magnetic resonance imaging and muscle strength

Summary A group of 12 sedentary medical students (1 man and 11 women aged 21–27 years) participated in a strength training programme for the trunk muscles lasting 18 weeks. The maximal isometric flexion and extension forces of the trunk muscles were measured before the training and at 18 weeks by dynamometer. The cross-sectional area of the back muscles, i.e. erector spinae, multifidus and psoas muscles, was measured from magnetic resonance images (spin echo sequence TR/TE 1500/80, slice thickness 10 mm) obtained at the L4–L5 disc level before the training, at 11 and 18 weeks. During training, no significant change in the body mass or body fat content was found. Muscle forces or muscle cross-sectional area were not related to body mass. There was a significant increase in both trunk muscle cross-sectional area (psoas muscle P<0.001 and back muscles P<0.01) and trunk muscle forces (flexion and extension forces P<0.01) during the training but no direct association between the muscle cross-sectional area and strength of the flexors and extensors was detected before or after the training.     

咀嚼时局部脑活动的功能性核磁共振成像

目的：应用功能性核磁共振成像（fMRI）探测人吸嚼时的大脑功能活动。方法：要求人在无任何其它躯体活动条件下咀嚼肌以10s运动20s休息的频率进行。选用8例成人冠状切面和横轴面的头部磁共振片,观察脑功能活动情况。结果：①在咀嚼时脑的广泛区域是激活的;②在相对应的咀嚼活动中有优势半球的激活区;③第I躯体感觉区激活的方式远较第I躯体运动区多样化;④在额叶中4例年轻观察对象出现了广泛的神经元激活区,但在老年人很少出现这样的激活区。结论：咀嚼活动除了它本身的功能运动外,在维持脑的活动方面具有重要的作用。同时也说明fMRI在研究活体人脑功能活动方面是一个相当有效的方法。     

Three-dimensional reconstruction of the hip muscles on the basis of magnetic resonance images

Summary MRI in combination with three-dimensional reconstruction is pre-eminently suitable for the study of the human musculoskeletal system in vivo in an accurate and detailed way. MRI provides the possibility of studying superficial as well as deep muscles under tension in the living state. Bones, muscles, tendons and adipose tissue are clearly visible. Parts can also be distinguished within a muscle. After reconstruction of the 2-D images the geometry of the muscles and muscle parts can be visualized from different angles. This leads to a deeper understanding of the biomechanics and functional anatomy of the musculoskeletal system of the human body. In this paper the morphology of the muscles around the hip was studied in three subjects in vivo on the basis of three-dimensional (3-D) reconstructions of two-dimensional (2-D) MR images.

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Reconstruction en 3D des muscles de la hanche par IRM

Résumé L'IRM associée à une reconstruction 3-D est particulièrement intéressante pour étudier l'appareil musculo-squelettique humain in vivo de façon précise et détaillée. L'IRM offre la possibilité d'étudier tant les structures superficielles musculaires que profondes sous contrainte in vivo. Les os, les muscles, les tendons et le tissu adipeux sont nettement visibles. On peut également au sein d'un muscle distinguer ses différentes portions. Après reconstruction des images 2-D, on peut visualiser la forme des muscles et de leur portions sous différents angles. Ceci permet une meilleure compréhension de la biomécanique et de l'anatomie fonctionnelle du système de l'appareil locomoteur du corps humain. Dans cette étude, la morphologie des muscles péri articulaires de la hanche a été étudiée chez trois sujets in vivo à partir de reconstructions 3-D des images 2-D obtenues en résonance magnétique.

     

Magnetic resonance image-based cerebellar volumetry in healthy Korean adults

The effects of age and gender on cerebellar size have not been established yet. To understand these effects, the area of cerebellar vermis and the volume of cerebellum were measured using serial magnetic resonance images of 124 Korean adults free of neurologic symptoms and signs. Cerebellar volume of male was significantly larger than that of female, although the size of vermis did not show significant gender difference. Correlation analysis revealed that cerebellar volume was not affected by aging. Regressional analysis demonstrated that female vermis had a tendency to shrink after age of 50, whereas male vermis and total cerebellar volume in both sexes were not altered with aging. The different response of vermis with aging and maintenance of cerebellum volume need to be more explored.     

Course of cerebral lesions in a patient with periarteritis nodosa studied by magnetic resonance imaging

Summary The course is reported of a patient with periarteritis nodosa who initially presented with neurological symptoms. Multiple cerebral lesions were documented by the first magnetic resonance imaging (MRI) investigation. The majority of these had disappeared completely in the follow-up MRI studies. In contrast to neurological improvement the patient eventually died due to multiorgan failure. Postmortem histological examination revealed no pathological findings in the brain except one single necrotic area already known from MRI. Remissions of histological and angiographic alterations in periarteritis nodosa have been described as local healing leading to fibrosis and scarring. Our findings suggest that restitutio ad integrum may occur, at least in cerebral lesions.Abbreviations PAN panarteritis nodosa - MRI magnetic resonance imaging - CT computerized tomography - CNS central nervous system